The <table> element forms the container for all the other
table-related elements. The many elements you can use between
<table> and </table> include
<caption>, <thead>, <tfoot>,
<tbody>, <colgroup>, <col />,
<tr>, <th>, and <td>.

A <colgroup> element has no content or code inside it if the
properties put forward in the <colgroup> element are to apply to
each column in the group. You can also use the <col/> element
inside a <colgroup> element to specify column properties for a
subgroup of the larger group.

Attributes:

<colgroup> can take the following attributes:

alignControls the horizontal alignment within the column group.
align can take on values of left, right, center,
justify, or char.

charSpecifies the alignment character for when align="char"
is used.

charoffPrescribes the offset distance from the alignment character.

spanTells the browser how many columns are in the group. The
default value is 1.

valignControls the vertical alignment in the column group.
valign can take on values of top, middle, bottom,
or baseline.

widthSpecifies how wide (in pixels or in terms of relative
width) the enclosed columns should be.

<td>, <th>

Type:

Container

Function:

Defines a cell in a table. <th> creates a header cell whose
contents will be rendered in boldface and with a centered horizontal alignment.
<td> creates a regular data cell whose contents are aligned flush
left and in a normal font weight. Vertical alignment for both types of cells is
middle by default.